Improvement in door-locks



Patented Sep. 12,1871.

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UNITED STATES COLUMBUS I. STEWART, OF BALTIMORE, MARYLAND.

IMPROVEMENT IN DOOR-LOCKS.

Specification forming part of Letters Patent No. 118,828, datedSeptember 12, 1871.

To all whom fit may concern:

Be it known that I, COLUMBUS I. STEWART, of Baltimore, in the county ofBaltimore, State of Maryland, have invented certain Improvements inLocks, of which the following is a specification:

The nature of my invention consists in a sliding stump attached to aplate working in guides formed on the bolt in combination with two slotsin the tumblers, as hereinafter more fully described.

Figure l is an elevation, showing the bolt thrown forward. Fig. 2 showsthe position ofthe stump when the master-key is used. Fig. 3 shows theposition of the stump when the principal key is used. Fig. 4 shows thesliding stump, the tumblers being removed; Fig. 5, plan of slidingstump; Fig. G, principal key; Fig. 7, master-key.

A is the frame of casing ofthe lock to protect and keep in the works. Bis a bolt, which is moved by keys or i, to which is attached the guidesc, in which the sliding plated works. eee@ are guides to support bolt Band tumblers fff. The sliding' plate d is provided on one side with thestump g, which works into the slots lL and h formed in the tumblers ffj'. The sliding plate d has on the under side a lug, 7c, upon which thespring m presses and forces the plate down. The tumblers f f fare eachprovided with a spring, n n u, which serve to keep them down.

When the key w is used the wards of keym serve to lift the tumblers fffso that the stump g will enter the lower slots h of the tumblers. The

tumblers fff and wards of key y are so arranged that the stump g onsliding plate d will work in slots h of the tumblers. By the use of thestump g on sliding plate d, working in guides c on bolt B, the tumblersf f j' being provided with two slots, h and h', the upper slots beingworked by one key, y, and lower slots being worked by another key, w, aset of locks may be constructed having the upper slots la. in tumblersff j' all alike, so that one key will operate all of the whole set, andthe lower slot h in tumblers ff f being all ditterently arranged, andrequiring a different adjustment in each lock, it will require adifferent key for each lock, all of which may be accomplished by the useofthe sliding plate d working in guides C, formed on bolt B, incombination with tumblers j'j'j', worked by a principal key, m, andmaster-key y.

I do not wish to be understood as claiming a bolt provided with asliding stump in combination with tumblers having one slot, as this isshown in patent granted to Steevenson & Edwards April 17, 1844, nor do Iclaim a bolt provided with a stationary stump in combination withtumblers having two slots, as this is shown in the patent granted to W.T. Munger April 18, 1871, but

I do claim as my invention- The sliding stump g attached to plate d,working in guides O formed on bolt B, in combina tion with slots h l1.in the tumblers, substantially as and for the purpose hereinbefore setforth.

O. I. STEWART.

Witnesses:

WM. S. G. BAKER, WM. G. STEWART.

